Photoscape (http://www.photoscape.org/ps/main/help.php?id=clonestamp) is free and will do animation a lot easier than GIMP. You just drag/drop your images, set the timing and other options. Then save with a file name.

How Tos (Animation):

GIF Animations Instructions: http://www.frontiernet.net/~steve_glimpse/animinst.html
How to create an Animated gif (Video): http://www.youtube.com/watch?v=Z93Z1v5dypE
How to Make a Animated GIF from a Video Clip: http://www.youtube.com/watch?v=1RMvoLyI_qs
How to Create Animated GIFs Using Photoshop CS3: http://www.wikihow.com/Create-Animated-GIFs-Using-Photoshop-CS3